Locomotive draft device



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.Patented Sept. 28, 1926.

Unirse s'rArEs .l JAMES JT. DEEGAN, OF SACRAMENTO, CALIFORNIA.

LOCOMOTIVE DRAFT DEVICE.

Application filed July 15, 192'5. sexier No. 43,788.

The present invention relates generally to improvements in locomotive fire boxes and has for its general object tonprovi'de means for uniformly vdistributing a draft of air to the fire bed and for introducing ka current of preheated air into the combustion vspace and from the rear end of the lire box7 whereby thorough combustion of the combustible gases is effected at the centralfand rear pon.

drawings forming part of the specification and; in whichl Figure 1 is a vertical longitudinal section taken through the lire box of a locomotive and showing portions of the locomotive by full and dotted lines, and further showing my invention partly in side elevation and in section.

Figure 2 is a transversesection on the line 2 2 of Figure 1, looking in the direction of the arrow.

In the drawings, 5 indicates the fire box of an ordinary locomotive 6. In carrying out my invention with the fire box 5 I provide at the rear end thereof an air chamber 7 extending vertically upward from the grate 8 and well into the combustion space of. the box 5 or7 in other words, to a point adjacent to the lower side of the door opening 9 of box 5. The chamber 7 extends transversely of the rear end of the box 5 and is defined by the presence of an outer wall 10 and an inner wall 11 arranged in spaced relation to the outer wall and formed of any suitable refractory material, such as tire brick. One or more open-ended passages 12 are formed in the inner wall 7 and located so as to eect communication between the combustion space of box 5 and chamber 7. In the embodiment shown a lower passage 13 is also provided in inner wall 11 and located below the combustion space of box 5, so that the chamber is placed in thermal contact with the box 5. The

upper end of chamber 7 is closed by a wall la vand in like manner the lower end of the said chamber isvclosed by 'a wall 15. An air inlet pipe 16 extends upwardly through the lower-end wall 15 and into` chamber 7. The passage through pipe 161 is controlled by a gate valve 17 to the cage A18 of which one end of the pipe 16 is connected, and a stem 19co-nnected to the gate valve -17' and alsoto a manually operable lever 20, preferably l'ocated in an accessible position-in the cabL 21', is provided for operating valve 17 to open andi` close.

A chamber 22 within cia-ge 18 is connected i toy an air supply pipe 23f-and communication between the chamber 22 and inlet pipe 1'16 is controlled by the gate valve 1173. Thev air supply pipe 23 is connected= to ablowe'r 24 ywhich may, as shown, be mounted upon the tender 25, av shaft 26 beingr employed" for connecting the blower 24' to a motor of4 any preferred type, such as a steam turbine 27 which is connected in operative relation to the boilerhead of' the locomotive by a pipe 28. i 29-is an air inlet pipe connected to cage 1-8 Vand in. constant communication with chamber 22. The pipe 29 extends forwardly and underneaththe grate 8 and its forward end is provided with an air distributor hood 3() of any preferred construction adapted for distributing jets of air outwardly and upwardly in a plurality of directions through the spaces between the bars of grate 8.

In the operation of the device as described and when valve 17 is open, the air upon entering chamber 7 from pipe 16 is readily heated by the heat from the fire bed passing through opening 13. The air thus heated is raretied and so entersthe combustion space through openings 12. In its raretied state the oxygen of the air more readily combines with the burning gases in the combustion space and thereby promotes combustion so that the heat of the resulting flame is of lmaximum intensity when it moves forwardly and impinges upon the forward end of the combustion chamber or bottom of the crown. sheet. This property of the present construction to promote combustion in the rear end portion of the lire boxis of importance, in that there results a thorough combustion ofall combustible gases so that practically no carbon is deposited within the tubes of the boiler, and the heat is applied where most needed, to wit, upon the crown sheet.

lt is to be noted that the result just mentioned on the part of the present construction, is to be readily distinguished from instances where the course of the draft is from the t'ront end ot the lire boi; and upwardly through the lire and into the ront end ot the combustion chamber. In the latter case combustion at the rear end of the fire box is relatively small and the partly consumed gases enter the boiler 'lines and operate to carbonize the same and, at the same time, the air moving upwardly through the front end of thc i'ire box, operates to reduce the temperature et the tire box below that had with the present construction.

lt is to be notedthat the location of the .hood 30 insures ot a uniformly distributed up-dra'lft through the tire bed to promote combustion therein. The present construction also eliminates the use of a relatively small oritice in the end of the exhaust pipe of the locomotive and located within the stack thereof, in that a relatively high velocity on the part of exhaust steam is not necessary to create a draft through the tlues necessary to draw a sufficient quantity of air into the tire box to promote combustion therein. Obvious then with the present construction, back pressure in the cy inders can be reduced to a minimum.

lt so desired, a tubular lead 3l may be extended from the feed water heating pipe 32 and connected to the inletvpipe 16 so that the exhaust steam in pipe 32 may be utilized in heating the air in chamber 7 in addition to the tire bed as previously described.

Although I have shown and described one embodiment out my invention, it is to be understood that the same is susceptible of various changes; and l reserve the right to employ such as may come within the scope ot the appended claim.

l claim:

In a locomotive tire box having the rear end thereof formed of outer and inner walls spaced one from the other to provide an intervening air chamber in thermal contract with the int rior ot' the lire box, the inner ot said walls havingl in its upper portion a transverse opening disposed so as to ell'ect communication between the chamber and the combustion space et the tire box, means for directing` a current of air upwardly t irough the chamber and outwardly through the opening thereoi'l and into the combustion space and further t'or directing a current of air upwardly through the tire bed and including` a power operated blower, an air taire-oil pipe connected to the blower, two conduits one ot which is directed into the lower end ot the chamber and the other of which is directed so as to distribute air underneath the lire box, a valve casing having separated portions to which the conduits are respectively connected and an intermediate portion connected to the air takeoff pipe, and a valve in the casing for controlling the passage of air from the take-olin pipe through one or both of the conduits.

JAMES J. DEEGAN. 

